After its publication in 1959, while Lettvin was a researcher at MIT, “What the frog’s eye tells the frog’s brain” quickly became one of the most cited papers in the Science Citation Index. In it, Lettvin and his co-authors made the first demonstration of “feature detectors” — the idea that specific neurons respond to specific features of a visual stimulus, including edges and contrast, curvature, movement and changes in light levels. They went so far as to describe certain frog retinal fibers as “bug detectors,” groups of cells that respond preferentially to small, dark objects that enter the visual field, stop, and then move around intermittently. Though it met with skepticism at first, the idea has had a profound and lasting impact on the fields of neuroscience, physiology and cognition.
In addition to his work on vision, Lettvin carried out many important studies of the neurophysiology of the spinal cord and information processing in nerve cell axons. Though he is best known for his work in neurology and physiology, he also published on philosophy, politics and poetry.
Early life and education
Lettvin, popularly known as “Jerry,” was born in Chicago on Feb. 23, 1920, to Ukrainian immigrant parents. In an autobiography written for the Society for Neuroscience, he called his Humboldt Park surroundings “materially poor but culturally rich” — indeed, Lettvin had his heart set on being a poet before his mother made the “irrevocable decision” that he was to be a doctor.
After high school, he began taking classes at the Lewis Institute before spending a year at the University of Chicago, where he met his longtime friend and collaborator, mathematician Walter Pitts. He earned both a BS and MD in 1943 from the University of Illinois, where he trained as a neurologist and psychiatrist.
After serving as a doctor in World War II, Lettvin had appointments at the University of Rochester and the Manteno State Hospital in Illinois, gradually transitioning from clinical practice to physiology research. He came to MIT in 1951 under Jerry Wiesner, then-director of the Research Laboratory of Electronics, who later served as MIT president. Along with Lettvin, Wiesner also hired Pitts and Warren McCulloch, and in doing so, assembled what would become a prolific team of neurophysiology researchers.
A master of debate
Lettvin was known for his remarkable debate skills, and would engage in well-reasoned argumentation with anyone on any topic, often extemporaneously. He would take any side, and believed that “if you can’t argue your opponent’s position, you have no right to your own argument,” his son, Jonathan, recalls.
In 1967, Lettvin took on powerful pro-drug figure Timothy Leary in a famous debate on the merits of LSD. In response to Leary’s claim that LSD offered its users a needed escape and gave rise to visionary and religious experiences, Lettvin argued that LSD was immoral because unlike lighter drugs, its users were more likely to be sucked in against their will, unable to break the cycle of living in an altered reality. He said: “The kick is cheap. The ecstasy is cheap. And you are settling for a permanently second-rate world by the complete abrogation of the intellect.”
Incredibly, Lettvin entered the debate with no advance preparation, as the professor originally scheduled to debate Leary had cancelled at the last minute, and the organizers struggled to find a replacement. “They came to his office as a last resort; he was up to his shirtsleeves in an experiment, but he walked right over and did it,” Jonathan Lettvin says.
The event received much attention from television and the press; The Boston Globe and many other sources extolled Lettvin‘s performance. Replays were used in high school anti-drug programs across the country.
In a tribute to Lettvin on his 60th birthday, William Pickard, a postdoc working with Lettvin in the 1950s, wrote: “Jerry has an unparalleled and unperturbable ability to think on his feet; and, having thought, to mesmerize an audience with his conclusions.”
Science and service at MIT
At MIT, Lettvin was renowned for being an outstanding mentor and a very energetic lecturer. Of his history of science class, his wife, Maggie, recalled: “He’d go in there and talk for three or four hours and the kids would bring their girlfriends, lunches, and just sit there forever.”
He and Maggie served as housemasters of the Bexley Hall dorm in the late 1960s and early 1970s, a time that was “both enlivening and exhausting” for them, he wrote in his autobiography. He was also one of the early directors of the Concourse Program, a freshman learning community that bridges the humanities and the sciences by exploring connections between disciplines such as literature and physics, or history and mathematics.
His approach to science often involved making observations that challenged key theoretical assumptions. In a 2007 interview, Lettvin said: “I’m a garbage picker-upper as a mode of science: I focus on the garbage truck. I look at the parts that others choose not to pay attention to.” He encouraged his students to ask difficult questions, to “tear apart what is already accepted.”
Lettvin is survived by his wife, Maggie; his three children, David, Ruth and Jonathan; and his six grandchildren. A memorial service is being planned; for more information contact Gill Pratt ’83, SM ’87, PhD ’89, a former MIT associate professor and former graduate student of Lettvin’s.